Abstract: In order to clarify the effects of planting density and plant growth regulators on the stalk traits of maize variety Nendan 19,in this study, the maize variety Nendan 19 was selected, and 3 density levels were set and etheph on two treatments of meridian compound（EC） and spraying clear water（CK） were used to study the effects of plant growth regulators and planting density on the stem traits of Nendan 19.The results showed that with the increase of planting density, the plant height of maize increased, the height of the gravity center moved up, the elongation of the basal internodes, the fullness of the basal internodes and the bending resistance decreased.EC treatment significantly decreased the length of internodes below the sixth node above the shoot, significantly increased the length of the internode above the seventh node above the shoot, slightly decreased the plant height, significantly decreased the height of the center of gravity and the height of the ear, and shortened the length of the basal internode.Thus, the lodging resistance of the stem was improved.It could be seen that under the conditions of high lodging risk such as frequent wind disaster lodging and excessive planting density, spraying plant growth regulators could significantly increase the flexural strength of corn stalks and the puncture strength of stem outer skins, and significantly reduce the ear position, gravity center height and lodging rate were conducive to high and stable maize yield.